Industrial and office wideband MIMO channel performance

Abstract

The aim of this dissertation is to characterize the MIMO channel in two very distinct indoor scenarios: an office building and an industrial environment. The study investigates the use of single- and dual-polarized antenna MIMO systems, and attempts to model the channel using well-known analytical models. The suitability of MIMO architectures employing either single or dual-polarization antennas is presented, with the purpose of identifying not only which architecture provides better average capacity performance, but also which is more robust for avoiding low channel rank. A measurement campaign employing dual-polarized 8×8 patch arrays at 2.4 GHz and 5.2 GHz is analyzed. For both environments the performance of three 4×4 subsystems (dual-polarized, vertical-polarized and horizontal-polarized) are compared in terms of the average capacities attained by these systems and their eigenvalue distributions. Average capacities are found to be only marginally different, indicating little advantage of dual-polarized elements for average performance. However, an eigenvalue analysis indicates that the dual-polarized system is most robust for full-rank MIMO communications, by providing orthogonal channels with more equal gain. The analysis of the analytical models shows that the Kronecker and Weichselberger models underestimate the measured data. Kronecker models are known to perform poorly for large antenna sizes and the performance of the Weichselberger model can be attributed to certain parts of the channel not fading enough.